Ta2O5 Nanowires: a novel synthetic method and their solar energy utilization

Abstract

Single-crystalline uniform Ta2O5 nanowires are prepared by a novel synthetic route. The formation of the nanowires involves an oriented attachment process caused by the reduction of surface energy. The nanowires are successfully applied to photocatalytic H2 evolution, contaminant degradation, and dye-sensitized solar cells (DSCs). The Ta2O5-based DSCs reveal a significant photovoltaic response, which has not been reported. As a photocatalyst, the Ta2O5 nanowires possess high H2 evolution efficiency under Xe lamp irradiation, nearly 27-fold higher than the commercial powders. A better performance of photocatalytic contaminant degradation is also observed. Such improvements are ascribed to better charge transport ability for the single-crystalline wire and a higher potential energy of the conduction band. This new synthetic approach using a water-soluble precursor provides a versatile way to prepare nanostructured metal oxides.